The present invention concerns the field of equipment, in particular equipment for motor vehicles or the like especially motor vehicle seats, and relates to a vehicle seat of this type equipped with a device providing protection, in particular, against impacts from the rear, and to a motor vehicle comprising at least one seat of this type.
At present, driver safety is of utmost importance in the production of new vehicles.
As structural elements and elements of comfort in direct contact with persons, the seats are essential to the safety of the occupants.
The seats, and in particular the seat backs, are markedly stressed especially in rear impact configurations and, if a single rotationally locked and latched lateral articulation is provided (standard equipment in numerous current motor vehicles), can lead to significant torsion in the frame of the back by the backward folding of the side remote from the articulation, which is likely to injure the occupants of said seats or even eject them.
Various solutions have already been proposed in an attempt to overcome this drawback and to increase the safety of the seats during an impact from the rear.
Thus, one of the solutions proposed involves reinforcing the structure of the frame of the back to increase its resistance to torsion.
However, to obtain at least minimal safety, this results in a significant increase in the cost and weight of the vehicle. Furthermore, the application of all the pressures received by the back in the region of a single articulation transforms this articulation into a very highly stressed element which is therefore susceptible to yield if its structure is not also reinforced, and this also involves a significant increase in its cost price.
It has also been proposed, to avoid reinforcing the back, to install two equivalent adjustable articulations on either side of the back to distribute the stresses better.
However, it is necessary precisely to synchronise the actuation and movement of these two articulations to avoid locking the back in position during adjustment or the twisting thereof, and therefore to provide additional expensive transmission mechanisms which have to be accommodated in the thickness of the seat and consequently increase its bulk.
Therefore, when continuously actuated articulations are used, it is necessary, for shifting the synchronisation rod outside the comfort zone of the back, to make use of complex, bulky and expensive transfer means (for example gears) owing to the necessary precision of fitting.
If discontinuous articulations are used, the transmission of movements from one to the other and the synchronisation thereof are achieved by means of a connecting rod, optionally shaped so as to leave the comfort zone of the back.
However, mere pressure in the region of the zone of the back comprising this rod can cause two articulations to unlatch and can therefore remove the hold for the back completely.
The object of the present invention is, in particular, to overcome the aforementioned drawbacks.
To this end, it relates to a vehicle seat, in particular motor vehicle seat, comprising at least one base and one back which is at least inclinable relative to said base by pivoting round at least one pivot axis, the seat being characterised in that it comprises a means of articulation or second means of articulation located on one side of the seat which is normally freely movable and can be automatically locked by the direct or indirect action of at least one means for detecting impacts or the consequences of an impact suffered by the vehicle under consideration.